You might be out of luck. I checked a couple of online places and couldn't find what you wanted. Directly from Extralite is 426 EUR with the "cheaper" bearings, 574 EUR with ceramics. (That's the non-VAT price too.)

My spokes (Sapim SuperSpokes) were special ordered (well it was a bit of an accident) from R2Bike a while back when I did the front wheel, and they're spec'd for the Extralite hub dimensions. Plus I have the HyperLefty front hub already.

I would avoid Extralite like the plague for reasons I've explained before (here) and consider the 2018 Carbon-Ti X-Hub SP with 56T Ratchet Ring instead. You can buy new spokes for the price difference.